: The long term goal of this project is to develop pregnancy diagnostic tests based on molecules produced by the placenta. One such candidate molecule is HLA-G, an unusual major histocompatibility complex class I protein. During Phase I of this project the investigators found that HLA-G is easily detectable, by immunoblotting, in amniotic fluid. This suggests that HLA-G measurements could be used in diagnostic assays that detect amniotic fluid analytes. In support of this hypothesis, the preliminary data suggest that a HLA-G immunoassay of cervicovaginal fluid could diagnose rupture of fetal membranes (ROM). Because Adeza has shown that a ROM test that detects fetal fibronectin (fFN) in amniotic fluid can also predict impending preterm delivery (PTD), the investigators are interested in the possibility that an HLA-G immunoassay can be adapted for this purpose. Accordingly, in this Phase II application, the investigator proposes to: 1. Construct HLA-G immunodiagnostic assays (immunochromatographic/ dipstick and ELISA formats) analogous to Adeza's existing technologies used to detect fFN in cervicovaginal fluid. 2. Determine if HLA-G levels in cervicovaginal fluid are indicative of ROM, and possibly of impending PTD. At the conclusion of the proposed Phase II experiments, the investigator will have identified a clinical use for an HLA-G immunoassay, thus rapidly proceeding to Phase III-commercialization and marketing of this test. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE